Update setup.py version to 0.4

Author: TianchengY

setup.py

@@ -6,7 +6,7 @@
 
 setuptools.setup(
     name="hammock_plot",
-    version='0.0',
+    version='0.4',
     author="Tiancheng Yang",
     author_email="[email protected]",
     description="Hammock - visualization of categorical or mixed categorical/continuous data",